Stop capturing video when screen is locked. Restart image capturing when screen is unlocked.

BUG=none
TEST=(with new screen locker on L13) Login from new user login. Notice that camera light is on. Lock the screen with Ctrl-Alt-L. Notice that camera light is off. Unlock the screen. Notice that camera light is on and video is shown.


Review URL: http://codereview.chromium.org/2847019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@50267 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 31 insertions, 1 deletions

diff --git a/chrome/browser/chromeos/login/user_image_screen.cc b/chrome/browser/chromeos/login/user_image_screen.cc
index b39bd30b..b8b6ed9 100644
--- a/chrome/browser/chromeos/login/user_image_screen.cc
+++ b/chrome/browser/chromeos/login/user_image_screen.cc
@@ -11,6 +11,8 @@
 #include "chrome/browser/chromeos/login/user_image_downloader.h"
 #include "chrome/browser/chromeos/login/user_image_view.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
+#include "chrome/common/notification_service.h"
+#include "chrome/common/notification_type.h"
 
 namespace chromeos {
 
@@ -29,6 +31,10 @@ const int kFrameRate = 40;
 UserImageScreen::UserImageScreen(WizardScreenDelegate* delegate)
     : ViewScreen<UserImageView>(delegate),
       ALLOW_THIS_IN_INITIALIZER_LIST(camera_(new Camera(this))) {
+  registrar_.Add(
+      this,
+      NotificationType::SCREEN_LOCK_STATE_CHANGED,
+      NotificationService::AllSources());
   if (!camera_->Initialize(kFrameWidth, kFrameHeight))
     camera_.reset();
 }
@@ -80,5 +86,19 @@ void UserImageScreen::OnCancel() {
     delegate()->GetObserver(this)->OnExit(ScreenObserver::USER_IMAGE_SKIPPED);
 }
 
+void UserImageScreen::Observe(NotificationType type,
+                              const NotificationSource& source,
+                              const NotificationDetails& details) {
+  if (type != NotificationType::SCREEN_LOCK_STATE_CHANGED ||
+      !camera_.get())
+    return;
+
+  bool is_screen_locked = *Details<bool>(details).ptr();
+  if (is_screen_locked)
+    camera_->StopCapturing();
+  else
+    camera_->StartCapturing(base::TimeDelta::FromMilliseconds(kFrameRate));
+}
+
 }  // namespace chromeos
 
diff --git a/chrome/browser/chromeos/login/user_image_screen.h b/chrome/browser/chromeos/login/user_image_screen.h
index f290304..609e5f6 100644
--- a/chrome/browser/chromeos/login/user_image_screen.h
+++ b/chrome/browser/chromeos/login/user_image_screen.h
@@ -8,13 +8,16 @@
 #include "chrome/browser/chromeos/login/camera.h"
 #include "chrome/browser/chromeos/login/user_image_view.h"
 #include "chrome/browser/chromeos/login/view_screen.h"
+#include "chrome/common/notification_observer.h"
+#include "chrome/common/notification_registrar.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 
 namespace chromeos {
 
 class UserImageScreen: public ViewScreen<UserImageView>,
                        public Camera::Delegate,
-                       public UserImageView::Delegate {
+                       public UserImageView::Delegate,
+                       public NotificationObserver {
  public:
   explicit UserImageScreen(WizardScreenDelegate* delegate);
   virtual ~UserImageScreen();
@@ -31,10 +34,17 @@ class UserImageScreen: public ViewScreen<UserImageView>,
   virtual void OnOK(const SkBitmap& image);
   virtual void OnCancel();
 
+  // NotificationObserver implementation:
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details);
+
  private:
   // Object that handles video capturing.
   scoped_ptr<Camera> camera_;
 
+  NotificationRegistrar registrar_;
+
   DISALLOW_COPY_AND_ASSIGN(UserImageScreen);
 };